Field of the Invention
The invention relates in general to a display matrix, a display device and its associated display method, and more particularly to a display matrix, a display device and its associated display method for synchronously displaying a source image.
Description of the Related Art
To publicize or market information, many companies mount huge television walls (display matrices) in the interior hallways or at outdoor locations with crowds. The object is to attract the attention of the masses via various types of display images displayed on the huge display matrix.
The conventional display matrix outputs the display images in parallel. That is, a distributor provides the source image to each display device. Such the method needs to additionally use a distributor, and cables between the distributor and each display device.
In order to decrease the installation cost, a display matrix serially connecting multiple display devices via a daisy chain is developed. In short, the display devices mounted in the daisy chain are connected in series according to the linking order, and the source image is sequentially transmitted between the display devices according to the serial connection order.
FIG. 1A is a schematic view showing a huge image composed of 4×2 display images. Referring to FIG. 1A, it is assumed that the display images 101, 102, 103, 104, 105, 106, 107 and 108 commonly constitute the huge image.
FIG. 1B is a schematic view showing a display matrix composed of 4×2 display devices. In FIG. 1B, there are four display devices in each row, and there are two rows of display devices to constitute the display matrix 10. The arrangement of FIG. 1B corresponds to that of the display images of FIG. 1A. In order to generate the effect of the television wall, the display devices in the display matrix 10 needs to commonly output the display image, and the content (source image) of the display image needs to be transmitted from a source display device 11 to subordinate display devices 12, 13, 14, 15, 16, 17 and 18 in order. That is, the source image is transmitted from the source display device 11 to the subordinate display device 12, then from the display device 12 to the display device 13, and so on.
Because the subordinate display devices 12, 13, 14, 15, 16, 17 and 18 need to receive the source image from the previous stage of display device in the daisy chain, the time points that the subordinate display devices 12, 13, 14, 15, 16, 17 displaying the source image are inconsistent. This is because the time point of receiving the source image by the display device is earlier than the time point of receiving the source image by the next display device. For example, the source display device 11 displays the source image at the first time point t1, and the subordinate display device 12 displays the source image at the second time point t2, wherein a transmitting time difference ΔT (for example, ranging from 3 ms to 10 ms) is present between the second time point t2 and the first time point t1. With the increase of the number of the display devices in the display matrix, the transmitting time difference caused by the serial connected display devices gets longer. Consequently, the delay phenomenon watched by the user on the display device gets more serious.